Equilibration and Typicality in Quantum Processes

TL;DR

This paper explores how forgetfulness and information loss emerge in quantum processes, explaining the transition from quantum coherence to classical irreversibility and quantifying the rate of memory effects in quantum systems.

Contribution

It provides a theoretical framework linking quantum dynamics with classical forgetfulness, bridging the gap between idealized theories and real-world quantum behavior.

Findings

Quantum processes exhibit forgetfulness due to information leakage.

The rate of memory effects can be quantified in quantum systems.

The framework explains the emergence of classical irreversibility from quantum dynamics.

Abstract

Forgetfulness is a common feature of nature. Moreover, without forgetfulness, repeatability would be impossible. Despite this, small systems constantly leak information about their state to their surroundings, and quantum mechanics tells us that this information cannot be deleted, invariably returning to influence their future behaviour. How can physical nature be forgetful if it is forbidden to forget? The results within this thesis bridge this gap between what we see in the real world and what idealised physical theories say, explaining the emergence of forgetful processes from closed quantum dynamics and allowing to quantify the rate at which memory effects become relevant.